function [err] = BK_LoadOn(sp,on)

PACKET_LENGTH = 26;
LoadCmdPacket = zeros(1,PACKET_LENGTH);
LoadCmdPacket(1:3)  = [ hex2dec('aa') 00 hex2dec('21')];
if(on)
  LoadCmdPacket(4) = 1;
else
  LoadCmdPacket(4) = 0;
end
  
LoadCmdPacket(end) = rem(sum(LoadCmdPacket(1:end-1)),256);  %Compute checksum
fwrite(sp,LoadCmdPacket);

 A = fread(sp,PACKET_LENGTH);
 if(length(A) == PACKET_LENGTH)
   if(A(4) == hex2dec('80'))
     err = 0;
   else
     err = 1;
   end
 else
     err = 1;
 end
end

